Update for anyone reading this in the future with a similar issue:
This is what fixed it for me,
I followed this guide and deleted the files "smbpasswd" & "shaddow"
However, this alone did not fix the issue, I also had to delete "network".
After doing all that, even with it plugged into my UPS (for power only, no usb at the moment), I was able to access it via the GUI/web interface in a browser! I am quite relieved, it has been a while!! 😮💨